Wordpress bad behavior since technical support got involved. Help!!

Yesterday I asked for help on the password protect content plugin. A nice support guy, Cole, said he'd help. I gave him my FTP access, and since then, things have gone downhill. I can't edit pages, I go to a white post.php screen. I can't insert images in pages, just get a white screen. Can't flush my W3 Total cache, white screen. Can't do anything in admin, white screen. Can't disable W3 Total cache without messing up WP Estore downloads (this didn't happen before, I've deactivated the W3TC before). I'm not sure what Cole did, and maybe he's not done, but my site is giving me all sorts of grief, and at this point I just want it to STOP and go back to the way it was before, and I will scrap the stupid password protect plugin til it's updated. Something is seriously wrong, maybe he messed with my AJAX or something, but please please please, my site is my livelihood and having it not work like this is costing me time and $ :slight_frown:

Daisy Peel